An object of mass 20kg moving at 10m/s due west collides with and sticks to an object of mass 10kg moving due east at 5m/s. What is the common velocity after collision, If both objects move together in the same direction?

When a lead acid car battery is recharged by the alternator, it acts essentially as an electrolytic cell in which solid lead(ii) sulfate is reduced to lead at the cathode and oxidized to solid lead(ii) oxide at the anode. suppose a current of is fed into a car battery for seconds. calculate the mass of lead deposited on the cathode of the battery.